Create loki labels for 'host' and 'appname'

Right now all dataplane logs end up in the same loki log stream. This patch will improve query and correlation performance under many common scenarios.

I'll do a quick demo about this tomorrow.

This is just CI, though, I think the real fix is is in our docs for the moment[1] - replace the link to the generic "Syslog receiver configuration example"[2] with this content, basically.

[1] https://docs.redhat.com/en/documentation/red_hat_openstack_services_on_openshift/18.0/html/configuring_observability/assembly_enabling-rhoso-observability-logging_observability
[2] https://github.com/openshift/cluster-logging-operator/blob/master/docs/reference/samples/observability.inputs-receivers.yaml

Author: csibbitt

ci/deploy-logging-dependencies/files/cluster_log_forwarder.yaml

@@ -19,6 +19,11 @@ spec:
         authentication:
           token:
             from: serviceAccount
+        labelKeys:
+          infrastructure:
+            labelKeys:
+              - host
+              - appname
         target:
           name: logging-loki
           namespace: openshift-logging